Pump check valve retainer



y 31, 1956 o. o. NEWMAN 2,756,683

- PUMP CHECK VALVE RETAINER Filed Aug. 6, 195] mmvron ODUS O. NEWMAN ATTORNEY United States Patent PUMP CHECK VALVE RETAINER Odus 0. Newman, Normandy, Mo., assignor, by mesne assignments, to ACF Industries, Incorporated, New York, N. Y., a corporation of New Jersey This invention relates to check valve retainers particularly for pumps of the type having a spring compressed between the movable wall of the pump and opposing pump wall.

Certain types of carburetor accelerating pumps utilize a coil compression spring bearing between the cylinder end wall and the opposing pump piston {or taking up slack in the pump operating linkage or for other purposes. It is my invention, as here disclosed, that this spring may be utilized as a retainer for a check valve seated in the pump end wall.

The main object of the present invention is to provide a novel simplified pump retainer check device.

A further object is to construct a spring as above mentioned so as to serve, in addition, as a check valve retainer.

These objects and other more detailed objects hereafter appearing are attained by the structure illustrated in the accompanying drawing in which:

Fig. l is a side view and partial vertical section showing an automotive carburetor embodying the invention.

Fig. 2 is an enlarged detail section of a part of the structure in Fig. 1 and showing a modification thereof.

Fig. 3 is a top View and horizontal section of the structure in Fig. 2.

Fig. 4 is a detail section similar to Fig. 2 but showing another modification.

Fig. 5 is a top view and section of the structure in Fig. 4.

The carburetor in Fig. 1 is of a more or less conventional automotive type having a downdraft mixture barrel 6 flanged at the bottom, as at 7, for attachment to the engine intake manifold (not shown). Adjacent the barrel is a constant level fuel chamber 8 enclosing an accelerating pump cylinder 9 in which works a pump piston 10 having a packing generally indicated at 11. A piston rod 12 has its lower extremity slidably received within a centrally apertured portion 13 of the piston and extending into a chamber 14 therein. Rod 12 is rigidly secured at 15 to a larger rod 16 connected by a small link 17 to an arm 18 rigid with a countershaft 19 rotatably mounted on top of bowl 8. A second arm 20, also rigid with countershaft 19, is connected by a link 21 to a crank 22 rigid with throttle valve shaft 23 journalled near the bottom of the carburetor barrel.

Piston 10 is constantly urged downwardly into its extended position with relation to piston rod 12 by a coiled spring 25 compressed between a washer 15a seated against the lower extremity of enlarged pump stem 16 and the top of apertured portion 13 of the piston. Within the expansible and contractible pumping chamber is a second lighter coiled spring 27 compressed between the fixed end wall 26 of the pump cylinder and the movable wall or undersurface of pump piston 10. Formed in cylinder end wall 26 is a recess or valve chamber 28 which receives inlet check valve 29 controlling pump inlet passage 30 connected by passage 31 to the constant level chamber through a screen 32. The bottom coil of spring 27,

lice

which seats upon cylinder end wall 26, traverses or overlies check ball recess 28 so as to retain the ball in. position.

In operation, opening of the throttle valve (not shown) which is rigid with shaft 23, causes depression. of. piston 10, through compression spring 25 producing pressure in the pump chamber 9 below piston 10, and, thereby, causing fuel to be injected into the carburetor barrel through the usual check valve pump outlet passage (not shown). Spring 25 causes a pump followup action, as is well known. Coil spring27 beneath the pump pist'omassists in attainment of the proper pump action and in eliminating slack in pump operating mechanism 17, 18, 19, etc. The spring also serves as a retainer for check ball 29 which, otherwise, would escape from its seating recess. Thus an extra check retainer part, as previously used, is eliminated.

In the modification in Figs. 2 and 3, the end coil 35 of compression spring 27a traverses recess 28a, as in the previous form, to maintain check ball 29a in position in the recess. However, the extremity 36 of the compres sion spring is bent axially and is frictionally gripped in an axial aperture 37 formed in a spring centering boss 38 projecting centrally from pump cylinder end wall 26a. Thus, when the pump piston is removed for inspection or repair, compression spring 27a will remain in position, preventing loss of the check ball. However, the compression spring may be removed by the application of pressure thereto.

In the modification in Figs. 4 and 5 the end coil 35a of compression spring 27b rests flat upon pump cylinder end wall 26b and traverses recess 28b, as in the previous forms, to act as a retainer for check ball 29b. A crossshaped centering projection 38a for the compression spring projects centrally from the cylinder end wall.

Consequently, in each form, no separate cage or key or other retainer means is required for the inlet check valve so that the structure is simplified and cheapened.

The invention may be modified and applied as will occur to those skilled in the art and the exclusive use of all modifications as come within the scope of the appended claims is contemplated.

I claim:

1. In a pump, an expansible and contractible pumping chamber having fixed and movable walls, a pump inlet passage in one of said walls, a valve chamber in said inlet passage having an opening facing the other wall, a check valve in said valve chamber for controlling said inlet passage and of less width than said opening so as to be admissible therethrough, and a coil spring stressed between said walls and having an end coil seated against said first mentioned wall and traversing said valve chamber opening for retaining said valve in position to control said inlet passage.

2. In combination with a pump chamber having opposing stationary and movable walls, a pump inlet passage to said pump chamber, a valve chamber in one of said walls connected with said inlet passage, a spring centering projection on said last-mentioned wall adjacent said valve chamber, said valve chamber having an inside opening to said pump chamber, a check valve in said valve chamber for controlling said inlet passage of less width than said opening so as to be admissible therethrough, and a spring stressed between said opposing walls, the end coil of said spring being received upon said centering structure and overlying said opening to retain said check valve in position to control said inlet passage.

3. In a pump, the combination of, an expansible and contractible pumping chamber having opposing fixed and movable walls, a pump inlet passage in one of said walls, and an inlet check valve in said inlet passage comprising a valve chamber opening into said pumping chamber, a

valve seat in said valve chamber opposite the opening to said valve chamber, a valve of a size to freely pass through the opening to said valve chamber to close said seat, and means to retain said valve in said valve chamber during operation of said pump including a coil spring compressed between said fixed and movable walls having one end coil engaging said one of said pumping chamber walls with a portion of the end coil of said spring overlying and closing the valve chamber opening to passage of said valve. 10

References Cited in the file of this patent UNITED STATES PATENTS 865,021 Dorment Sept. 3, 1907 15 4 Thompson Nov. 23, 1909 Dybens Dec. 14, 1926 Mollberg Dec. 6, 1938 FOREIGN PATENTS Great Britain Nov. 10, 1900 Great Britain Nov. 24, 1913 France Feb. 23, 1914 

